GB878257A - Bonding urethane polymers to rubber and adhesive therefor - Google Patents

Abstract

An adhesive material suitable for bonding a urethane polymer to another synthetic rubber or natural rubber comprises the reaction product of a polyglycol and an alkyl benzene diisocyanate of the formula: <FORM:0878257/IV (a)/1> wherein R is an alkyl radical containing more than 4 carbon atoms and is straight or branched chained, in a mol ratio of 1 mol of the polyglycol to 2 mols of the diisocyanate. The re action product may be mixed with a minor amount, e.g. 2,5% by weight, of tributylamine as an accelerator and the mixture is diluted with an organic solvent such as benzene, hexane, ethyl acetate or acetone. In Examples (3) two moles of amyl-benzene diisocyanate are reacted with one mole of a polyglycol; (4) dodecyl benzene diisocyanate is similarly reacted. The products are used for joining urethane rubber to GR-S stock. Nitrile rubbers, butyl rubbers and polymers prepared by treating sodium polysulphides with dihalogenated materials can also be bonded. In comparison processes a polyester is prepared from adipic acid, propylene glycol and ethylene glycol and is reacted with excess toluene diisocyanate. Diamino toluene is added to the product. Attempts were made to bond portions of the uncured and cured mixture to unvulcanized GR-S rubber by contacting the materials with heating under pressure, but no bonding was effected.